Polymerization of olefinic hydrocarbons



United States Patent 3,231,547 POLYMERIZATION 0F OLEFINIC HYDRO- CARBONS Jules Darcy, Raymond A. Stewart, and Lloyd A. McLeod,

Sarnia, Ontario, Canada, assignors to Polymer Corporation Limited, Sarnia, ()ntario, Canada No Drawing. Filed Apr. 3, 1961, Ser. No. 100,012 Claims priority, application Canada, June 3, 1960, 800,341 Claims. ((11. 26085.3)

The present invention relates to the polymerization of olefinic hydrocarbon compounds. It relates particularly to the ionic copolymerization of isobutylene with polyolefinic hydrocarbon compounds to form copolymers thereof.

It is known that high molecular weight copolymers of isobutylene and isoprene may be obtained by copolymerizing these monomers in solution in an inert diluent at very low temperatures i.e. about 100 C., with the aid of Friedel-Crafts catalysts. These copolymers, more commonly known as butyl rubbers, may be vulcanized and are characterized by low unsaturation and high impermeability to gases. They have attained very wide commercial acceptance, particularly in the manufacture of air retaining liners for automobile tires.

Recently there have been developed novel processes for the polymerization of alpha-olefins while dissolved in inert diluents such as pentane and hexane, using specially prepared catalysts. These catalysts are commonly referred to as stereospecific catalysts and may be defined broadly as being complexes formed by mixing reducible heavy metal compounds with organo-metallic reducing agents. The heavy metals most frequently used are those of Groups IVB, VB and VIB of the Periodic Table as exemplified by titanium, vanadium and chromium. Typical reducible heavy metal compounds are the halides, oxyhalides, alkoxides, acetates, etc. of titanium, vanadium and chromium. The organo-metallic reducing agents most often used are those-compounds based-0n the metals of Group HIA of the Periodic Table with aluminum being preferred. Examples of such reducing agents are the trialkyls, dialkylmonohalides, monoalkyldihalides, hydrides, etc. of aluminum, gallium, indium and thallium.

Inert diluents such as pentane, hexane, heptane and benzene invariably have been present as solvent media for these polymerization reactions, and have been employed in amounts generally greater than 200% by weight and usually varying from 300900% or more by weight with respect to the total weight of the monomeric reactants.

When attempts were made to copolymerize isobutylene with polyolefinic hydrocarbon compounds in these systems, it was found that not only were yields low but that copolymers could not be obtained. In other Words, it was found that the bulk of the polymeric product obtained was comprised mostly of homopolymers of the polyolefinic hydrocarbon compound with the isobutylene remaining substantially unreacted.

It is the primary object of this invention to provide a process for obtaining high yields of copolymers of isobutylene with polyolefinic hydrocarbon compounds.

Another object is to prepare vulcanizable, high molecular weight, rubbery copolymers of isobutylene with polyolefinic hydrocarbon compounds by using a polymerization catalyst formed by mixing a reducible heavy metal compound with an organo-metallic reducing agent.

These and other objects of the present invention are attained by a process comprising contacting 75.0-99.9 parts by weight of isobutylene with 0.125.0 parts by weight of a polyolefinic hydrocarbon compound in the presence of a catalyst formed by mixing a reducible metal ice compound of a heavy metal from Groups IVB, VB and VIE of the Periodic Table with an organo-metallic reducing compound based on a metal from Group IIIA of the Periodic Table, the molar ratio of said organo-metallic reducing compound to said reducible heavy metal compound being less than 1.3, at a temperature lower than 0 C. in the presence of less than 200 parts by weight of inert reaction diluent per parts by weight of polym erizable hydrocarbons.

In carrying out the copolymerization of the isobutylene with the polyolefinic hydrocarbon compound, it is convenient to premix the reactant monomers and to preform the catalyst before contacting the monomers with the catalyst. Alternatively, the catalyst maybe formed within the liquid reactants by adding the catalyst components individually to the reactants in the absence of diluent. When the copo-lymerization is to be carried out in the presence of a diluent, it may be more convenient to preform the catalyst in part or all of the diluent pnior to contacting with the monomers.

The employment of a diluent carries with it a prerequisite that the amount of diluent be restricted to less than 200 parts by Weight per 100 parts by Weight of reactant hydrocarbon compounds. Preferably, diluent usage should be limited to less than 100 parts by Weight per 100 parts by weight of reactants since the yield of copolymer decreases with increasing solvent to monomer ratios.

While useful polymers may be produced by copolymerizing the isobutylene with any polyolefinic hydrocarbon compound, it is desirable that the polyolefine be a conjugated diolefine possessing a vinylidene group in its molecular structure. The most useful copolymers will be obtained with conjugated diolefines containing 4 carbon atoms in the unsaturated chain. Illustrative lot the more suitable diolefine monomers are butadiene-l,3, pentadicue-1,3, Z-methyl butadiene-l,3, 2,3-dimethyl butadiene- 1,3 and hexadiene-l,3. The preferred compounds are Z-methyl butadiene-l,3 and butadiene-1,3. The use of less than 25.0 parts by weight of polyolefine per 100 parts by weight of total monomers is preferred since the reaction rate is retarded with increasing amounts of .polyolefine.

As indicated, the catalyst may be prepared by mixing a reducible metal compound of a heavy metal from Groups IVB, VB and VIB of the Periodic Table with an organo-metallic reducing compound based on a metal from Group IIIA of the Periodic Table. Typical reducible heavy metal compounds are the halides, oxyhalides, alkoxides, acetates of titanium, vanadium and chromium. Excellent results can be obtained with titanium tetrachloride. Examples of the organo-rnetallic reducing compounds are the trialkyls, alkyl halides and hydrides of aluminum, gallium, indium and thallium. Aluminum alkyls are generally to be preferred with excellent results being obtained with the less expensive compounds such as aluminum triisobutyl and aluminum triethyl. The amount of catalyst used is not critical but it does atlect the reaction rate and molecular weight of the resulting polymer. Reaction rate increases and molecular weight drops with increasing amounts of catalyst. Thus the amount of catalyst employed will be influenced by the desired conditions for the reaction and properties of the desired polymer product,

While the amount of catalyst used is not critical, its composition is of some consequence. Thus in preparing the catalyst it is important to maintain the molar ratio of organo-metallic reducing compound to reducible heavy metal compound at a value lower than 1.3 and preferably below 1.0 since yields of copolymer begin to drop rather sharply as the ratio increases from 1.0 to 1.3.

The temperature at which the reaction is carried out -mers decreases.

summarized in Table II.

affects the molecular weight of the polymers obtained. Thus when reaction temperatures are maintained below C. and preferably below about 15 C. solid polymers of high molecular weight are obtained. As reaction temperatures rise above about 15 C. and especially above 0 C. the molecular weight of the recovered poly- Liquid polymers may be expected at reaction temperatures above about 25 C.

The following examples will serve to illustrate the invention more fully.

EXAMPLE I Polymerization of isobutylene with isoprene in presence 0] large amounts of solvent To each of three dry 7-ounce polymerization bottles previously flushed with nitrogen and capped there were added 40.0 cc. of dry benzene, 2.5 millimoles of pure aluminum triisobutyl and 2.5 millimoles of pure titanium tetrachloride. The contents were aged at room temperature for 30 minutes following which a further addition of 90 cc. of dry benzene was made to each bottle. Various amounts of isobutylene and isoprene were added to the bottles and polymerization was allowed to take place at C. and 50 C. for 60 hours. 40 cc. of ethanol containing 0.5 weight percent of dissolved phneyl-beta-naphthylamine (PBNA) were then mixed with the contents of each bottle to stop the polymerization and precipitate the polymer. Each mixture was heated to boiling-to extract and destroy the catalyst residue. The treatment with alcohol-PBNA solution was repeated to assure the recovery of a pure polymer containing a small amount of the PBNA antioxidant. The polymer obtained from each bottle was then thoroughly dried and subjected to infrared analysis to determine its composition. The results are summarized in Table I.

TABLE I Bottle 1 2 3 Solvent (benzene), cc 130 130 130 Aluminum triisobutyl, millimoles 2. 5 2. 5 2. 5 Titanium tetrachloride, millimoles 2. 5 2. 5 215 Isobutylene, cc 22. 5 12. 5 6. 0 Isoprene, cc 2. 5 12.5 18. 0 Polymerization te 5 50 5 Polymerization time, hours 60 60 60 Yield, grams 1. 1 7. 3 10. 2 Yield, weight percent on 7. 0 43.0 64. 2 Weight percent isoprene in polymer. 99. 5 99. 5 100 Weight percent isobutylene in polyrn 0. 5 0. 5 0

The infra-red analysis showed that the polymers are essentially all homopolyisoprenes with traces of isobutylene showing in the polymeric structure of Samples 1 and 2. These results indicate that no copolymers are obtained when isobutylene and isoprene are copolymerized at high solvent to monomer ratios.

A further series of four polymerizations were carried 'out to verify the foregoing results and to check the eifect at lower solvent to monomer ratios. The results are TABLE II Bottle 1 2 3' 4 Solvent (pentane), cc 30 60 75 135 Aluminum triisobutyl, millimoles 2. 5 2. 6 2. 5 2. 5 Titanium tetrachloride, millimoles 2. 5 2. 5 2. 5 2. 5 Isobutylene, cc 7. 5 7. 5 7. 5 7. 5 Isoprene, cc 7. 5 7. 5 7. 5 7. 5 Polymerization temp., 0. 13 13 13 13 Polymerization time, hours. 16 16 16 16 Yield, grams 4.85 4. 4 2. 7 2. 0 Yield, wt. percent on monomers 49. 5 45.0 27. 5 20.4 We1ght percent isoprene in polyme 99 100 98 98 7 Easy processing channel black Zinc oxide -2 5 cur Modulus at 300% elongation (p.s.i.): 60 Y 10' CHIP These results show that at solvent to monomer ratios as low as 2.0 only homopolyisoprene is formed and that the iso butylene monomer remains essentially unreacted.

EXAMPLE II Copolymerization of isobutylene with isoprene in the absence of solvent To a series of eight dry and capped 7-ounce polymerization bottles there were added by means of a syringe varying amounts of titanium tetrachloride and aluminum triisobutyl. The bottles were cooled to 75 C. and 40.0 cc. of isobutylene containing 3.0% by volume dissolved isoprene were added to eachbottle. Polymerization was allowed to proceed at 75 C. for 40 hours. The polymer product in each bottle was purified and recovered .with ethanol-PBNA solution as described in Example I.

The results are summarized in Table HI.

Samples of the polymers obtained from bottles 5, 7 and ,8 were compounded according to the recipe given in Table IV. Tensile strength, modulus, elongation and other tests were determined on each of the samples. These results are summarized in Table V.

TAB-LE 1V Parts-by weight I Y of polymer Polymer 50 TABLE V vulcanization temperature Bottle 5 Bottle 8 Tensile strength (p.s.i.):

10 cur 12.5. cure 20 cure 25 cure 40 euro 50 cure 12.5 cure 20' cure 25 cure 40' cur I 50 cure v The above results indicate that true copolymers of iso- The results are summarized in Table VII. butylene with isoprene of high molecular weight are TAB-LE VII obtained in the absence of solvent during the polymerizav tion process and that these copolymers may be com- Bottle 2 3 4 5 V 6 V pounded and cured to yield rubbery vulcanizates' possess TiCl ,millimoles (1) 2.0 2.0 2.0 2.0 2.0 2.0 2.0 mg attractive physical properhes. The high yield of poly- Amsobutym, mimmoles i (2 0.00 0.99 1. 32 1.65 1.98 2. 31 2. 64 mer mdlcats that the lsobutylenfi polylnerlzlng slnce' Ratio (2)/(] 3 (L50 66 1 3 0 9g 1 16 1 32 not enough isoprene was charged to give these y1elds. The high tensile strengths and increases in modulus with time 10 voiume pefqent m, iei grams of vulcanization indicate that isoprene was polymerized into the molecular structure of the polymer since polyiso- 3-2 iE-g -2 butylene is not vulcanizable with sulfur. 1215 111 .4 1115 619 019 016 III:

Mole ercent unsaturatmn EXAMPLE III p 2.6 2.3 2.3 1.9 1.1 Copolymerzzatzon of zsobutylene with zsoprene m the 3.1 3.3 3.5 2.0 1.2

absence of solvent 20 1 t 1 The polymerization of Example II was repeated usmg a Intnnsm mm t 0 uene 10% solution of isoprene in isobutylene. The results 5% 1 4 1 4 1 5 1 4 are summarized in Table VI. 1.2 1.1 1.2 1.1 1 0.91 0.86 0.95

All polymers on which intrinsic viscosities were determined were completely or almost completely soluble in toluene. E TABL VI These results indicate that best y1elds of polymers will 0 00 be obtained at aluminum trnsobutyl/titamum tetrachlo- Bottle 13345678910..

r1de ratios below about 1.0 depending on the concentra- 1011 (millimoles) 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 of dlolefin m h monomenc mlxture' Amsobutyba (mini- The polymers obtained from bottles 1, 2, 3 and 4 1n gg g gg the series where 20 volume percent butadiene-1,3 was pres ram 12.0120 16.7 16.0 15.4 15.7 17.7 17.4 20213.3 ent in the monomeric mixture were compounded accord- Yieldvwtpement 011 ing to the [recipe given in Table IV and vulcanized at m o ers 4s. 0 4s. 0 60. s 64. 0 61.7 62.8 70.8 69. 6 80.8 73. 2 Tengi le s trength, p.s.i. 307 F. The vulcanlzates were tested to determine the1r cure at 1:365 tensile strengths, percent elo-ngations at break and moduli.

' The results are summarized in Table VIII.

TABLE V111 Curing time, Modulus, p.s.i. at elongation ot- Tensile Elongation, Bottle minutes at strength, percent at 307 F. p.s.i. break 1 20 100 325 490 740 1, 780 720 40 225 Y 370 650 900 1, 975 650 so 270 490 825 1, 250 1, 975 560 2 20 170 240 395 590 1, 620 725 40 195 340 560 850 1, 900 680 so 240 395 695 1; 000 1, 890 590 3 20 195 310 540 5 1, 950 715 40 24.0 440 735 1,110 2,090 620 255 500 850 1, 255 2, 580 4 20 260 450 1, 775 830 40 255 410 650 *1, 250 550 80 325 550 870 1, 975 060 *Flaw in specimen.

These results show that good yields of copolymers are obtained in the absence of solvent when higher proportions of diolefine are employed.

EXAMPLE IV Copolymerization of isobutylene with buradiene Twenty-one 7-ounce polymerization bottles were charged with 40.0 cc. of 5, l0 and 20 volume percent solutions of butadienealjfin isobutylene and various ratios of titanium tetrachloride and aluminum triisobutyl catalyst components. The catalyst components were added to the bottles at room temperature in the presence of about 5 cc. of pentane. The bottles were cooled to 75 C. and the monomers previously cooled to 20 C., were then added. The polymerizations were allowed toproceed at -75 C. for 16 hours. The polymer product in each bottle was purified and recovered with ethanol- PBNA solution as described in Example 1. Yield, percent unsaturation and intrinsic viscosity were determined on each sample.

These results show that copolymers of isobutylene with butadiene-1,3 are obtained and that these copolymers may be vulcanized to give products having attractive physical properties.

EXAMPLE V .Copolymerization of isobutylene with isoprene in the presence of various amounts of solvent Forty-five 7-ounce polymerization bottles were charged with 40.0 cc. of isobutylene containing 3% by volume of dissolved isoprene. Various solvent/ monomer and aluminum triisobutyl/titanium tetrachloride ratios were used. The polymerizations were carried out at -75 C. for 20 hours in three series of 15 bottles each. In series A the bottles were dried in an electric oven at 120 C., flushed with nitrogen While still hot, capped, cooled and pressurized with nitrogen before addition of the catalyst and monomeric components. In series B the bottles were not flushed or pressurized with nitrogen but merely capped while still hot after removal from the electric r a 4. The process of claim 1 whereinthere is no inert reaction diluent present during the polymerization.

5. The process of claim 1 wherein the temperature of polymerization is lower than 15 C.

6. The process of claim 1 wherein the organo-metallic reducing compound is an aluminum alkyl and the reducible heavy metal compound is a titanium halide.

7. Aprocess comprising contacting 75.0-99.9 parts by weight of isobutylene and 0.1-25.0 parts by weight of a conjugated diolefinic hydrocarbon compound containing four carbon atoms in the unsaturated chain in the presence of a catalyst formed by mixing titanium tetrachloride with aluminium triisobutyl, the molar ratio of said aluminium triisobutyl to said titanium tetrachloride being less than 1.0, and in the presence of less than 100 parts TABLE IX The purpose of these various bottle treat- .The polymerizations were repeated using and The results are summarized in Table IX.

drying oven.- 'In series C the bottles were dried in a steam oven at 75C. and were not flushed or pressurized with nitrogen but merely capped While still hot as in series B.

presence of small amounts of oxygen would have any efiect on the subsequent polymerizations.

meric product in each bottle was purified and recovered as described in Example I. The polymeric products ob tained from a number of the A series polymerizations were subjected to infra-red analysis to determine the .2 n .a 33338 0 2211 0 W00 0 00 0 M00 a u t mam m ded au S e e Lo mr mmm m m Y m m m o 0 00 2 1D 1 27m 3 66666 SE0 Rh w hu 22222 6%3 2m22 4 22 t.m4 0 m aw r m e n e 02201 0 .00 0.00 0 .00 .l. I C e S 1 WMQ fl m m T 0 t N 013 2 .72 0 .22 2.72 h hhha 522 0 10 ms n.0 m0 0 n.m3 0 W m mmm mm unflu e n .L eh m C .e a. m3 3 2151 3 9 2H51 palm aw m .B m M .2201 0350 1355 0050 t 5 .Eh 41 ea 36 1 .1 1 Wd y mt 00 9922 5222 9822 U0 r. m m b E a. e m 02211 2210 L403 2710 flb n lu T m r 4 d m.mC m o wAommmn d P. ro 3 0 0W00 uou3fiw 0920 mmm .mmwr mmam F y @2201 1 .12 1 70 17 12 cu r. e h M 0d C C CHC C S D a e r si a 449 2 5 eh no B45566 4. .02 0370 4.62 .1 WO O w T 9999 0220 1. 1.5 1 34 2 6 1H te o bs I11111 1 mmws tsm u 10 "OM07 8m1m0m07 ma md mmwcmw a U 8660/w 5 220 14 L2 o 4 2 .m mw mmm R O W pd y 81693 H 0 1822 4 414 ln22 m en e mh 232006 "2201 4239 84 12 4 n h Va m a h 150009 39 g a T C a 9 a a a n 11 21 11 .m 0 4 07 8030 5239 8036 42110 lomw 4 5 88 M 6 m 1% 22223 t 4 57 9195 2674 9995 O 5 O %2100 21 1 7 U 4. 5 S 6 S .1 6 S 5 4. awmmhwm m W n W 427 ..40 1.0. 4.4 0 tn la CW fegun n 0. m 1 O O 02 L0 0 1 .0 0w 9 .L O e n m 6 I X 0 m um. O a r a 1 .11 .1.11 ybw ab nmt mfmvnumno 417 9 M39 3.m80 9 W39 wh m w mfmGomo 52100 n mun n man m mun c mmnm mw9wv mmmm r O 0h S a a mo C.d ab 4 7 8525 8056 8625 f e e :1 "21.00 7 2 &4 6 4 0 2 7 7 214 o rh sfib n .m ww d nm 1 11 1 21 1 11 fi.WaM mW WHO dmhme a st n e m 1 hus -nd7r. rm HVZL h .1 33 a I. a. wnetmhcywnmgpiynar hS S .1 n HT. m: m .m.. f mflto h tvT "11% TI sm v..m m w w m 0 e t t e n .1 1 151. .m... h a a me m da d m D. t dh a t S I .nI .w me m n1ma .ma a: n. a: m w nrnm a o da n I ...m...: v fi sg Pm I .m.. H... aw: mdmmmmwmm nmnm mewm .O.. IS 0 h .25 .w n doenw e n 1.... mmam mmmm mmmm am mm om m nnmmnm wo. amen. amen am n .w mwil mnmkme c mn n mn d ,ei doyeoabooepcyewc e ir l.ll m hmm M.Mm mi .HaSPm ml .1 E e r. .m mm .m mn .w m w me e i o s 0 Pa .1 r e e. w v T e d i cc a y. v. 1? 53 nd m nnmo m deanu... o nn .n 1 O f. .t. mmmmnannnoodnno nroo wm m mw mwm mmam wmw mw w wnfiibfi. mn ram umew o h z iiii mmnmp enm t o q. t b if m m rrrr rrnronnn f e 1 e.m A m n0 weeeeweeen weeee O ma hP U .E SSSS. SSSS%SSSS G e O D t u 6T w.b m m 1 ac o h 0 3 V 8 m 11 b T sRW. W m mafimflim w m wmmm mH men-ts was to determine if traces of moisture and the 5 by volume solutions of isoprene in isobutylene. The polyvweight percent isoprene in their molecular structures.

metallic reducing compound to said reducible heavy metal 55 compound being less than 1.0, at a temperature lower FOREIGN PATENTS than 0 C., and in the presence of less than 100 parts by 827,365 2/1960 Great Britain weight of inert reaction diluent per 100 parts by weight of polymerizable hydrocarbons. g 7 OTHER KEFERENCES 2. The process according to claim 1, wherein the con- Gaylord and Mark: Llnear and Stereoregular Addrjugated diolefinic compound is a hydrocarbon compound t y s? lntersclence Pubhshers, New York, containing four carbon atoms in the unsaturated chain. 1959, PP-

3. .The process of claim 1, wherein the resulting reaction is allowed to proceed for not more than 50 hours at JOSEPH H Pr'mary Exammer'. a temperature down to --100 C. LEON J. BERCOVITZ, Examiner. 

1. A PROCESS COMPRISING CONTACTING 75.0-99.9 PARTS BY WEIGHT OF ISOBUTYLENE WITH 0.1-25.0 PARTS BY WEIGHT OF A CONJUGATED DIOLEFINIC COMPOUND CONTAINING A VINYLIDENE GROUP IN THE PRESENCE OF A CATALYST FORMED BY MIXING A REDUCIBLE METAL COMPOUND OF A HEAVY METAL FROM GROUPS IVB, VB AND VIB OF THE PERIODIC TABLE WITH AN ORGANOMETALLIC REDUCING COMPOUND BASED ON A METAL FROM GROUP IIIA OF THE PERIODIC TABLE, THE MOLAR RATIO OF SAID ORGANOMETALLIC REDUCING COMPOUND TO SAID REDUCIBLE HEAVY METAL COMPOUND BEING LESS THAN 1.0, AT A TEMPERATURE LOWER THAN 0*C., AND IN THE PRESENCE OF LESS THAN 100 PARTS BY WEIGHT OF INERT REACTION DILUENT PER 100 PARTS BY WEIGHT OF POLYMERIZABLE HYDROCARBONS. 